1. Technical Field
The present disclosure relates to a shift register, and more particularly, to a shift register that is able to suppress ripples.
2. Background of the Disclosure
Generally, a display panel includes a plurality of pixels, a gate driving circuit, and a source driving circuit. The gate driving circuit includes a plurality of stages of shift register circuit and is used to provide a plurality of gate driving signals for turning on and off the pixels. The source driving circuit is used to write the data signal into the turned-on pixels. The shift register is a circuit commonly used for implementing the function of the gate driving circuit. The shift register can include a plurality of stages of shift register circuit and each stage of shift register circuit is used to provide the scan signal for turning on and off a row of pixels according to the corresponding clock signal.
FIG. 1 shows a shift register circuit 100 according to related art. Each the shift register circuit 100 includes a first switch T1 for outputting the scan signal GN. The first switch has a first terminal for receiving the clock signal CK, a second terminal for outputting the scan signal GN of the shift register circuit 100, and a control terminal for receiving an internal reference voltage VQ, wherein the second terminal is also connected to next one shift register circuit (or namely neighbor shift register circuit) 100. When the internal reference voltage VQ and the clock signal are of high voltage level, the shift register circuit 100 can output the scan signal GN with high voltage level correspondingly. However, since the clock signal CK switches between high voltage level and low voltage level periodically, the shift register circuit 100 may induce ripples on the internal reference voltage VQ due to the coupling effect on the first switch T1 caused by the clock signal CK when the clock signal changes from low voltage level to high voltage level even when the internal reference voltage VQ should be of low voltage level, which may further cause wrong operations of the scan signal and wrong charging of the display panel.
As the resolution of the display panel becomes higher and higher, the time for the source driver to transmit a bit of pixel information is also shortened. Therefore, how to reduce the ripples caused by the clock signal on the shift register circuit instantly and effectively has become a critical issue to be solved.